The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A280910 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A280910

Characteristic sequence of A277238.
(history; published version)

#17 by Joerg Arndt at Fri Apr 05 12:00:01 EDT 2019

STATUS

reviewed

approved

#16 by Wesley Ivan Hurt at Fri Apr 05 10:08:32 EDT 2019

STATUS

proposed

reviewed

#15 by Michel Marcus at Fri Apr 05 09:37:11 EDT 2019

STATUS

editing

proposed

#14 by Michel Marcus at Fri Apr 05 09:37:06 EDT 2019

PROG

(PARPARI) A280910(n) = if(n<=1, n, my(b = binary(n)); if ((#b % 2) && (b[#b\2+1] == 0), return (0)); vecmin(vector(#b\2, k, bitxor(b[k], b[#b-k+1]))) == 1); \\ Antti Karttunen, Dec 23 2018, after isok function given in A277238 by Michel Marcus, Oct 07 2016

STATUS

approved

editing

Discussion

Fri Apr 05

09:37

Michel Marcus: typo

#13 by Susanna Cuyler at Sun Dec 23 16:13:40 EST 2018

STATUS

proposed

approved

#12 by Antti Karttunen at Sun Dec 23 15:36:47 EST 2018

STATUS

editing

proposed

#11 by Antti Karttunen at Sun Dec 23 15:25:05 EST 2018

LINKS

<a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>

#10 by Antti Karttunen at Sun Dec 23 15:23:43 EST 2018

LINKS

Antti Karttunen, <a href="/A280910/b280910.txt">Table of n, a(n) for n = 0..65537</a>

<a href="/index/Ch#char_fns">Index entries for characteristic functions</a>

#9 by Antti Karttunen at Sun Dec 23 15:20:05 EST 2018

DATA

0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1

OFFSET

1

0

PROG

(PAR) A280910(n) = if(n<=1, n, my(b = binary(n)); if ((#b % 2) && (b[#b\2+1] == 0), return (0)); vecmin(vector(#b\2, k, bitxor(b[k], b[#b-k+1]))) == 1); \\ Antti Karttunen, Dec 23 2018, after isok function given in A277238 by Michel Marcus, Oct 07 2016

EXTENSIONS

Term a(0) = 0 prepended and more terms added by Antti Karttunen, Dec 23 2018

STATUS

approved

editing

#8 by N. J. A. Sloane at Tue Jan 10 19:44:16 EST 2017

STATUS

proposed

approved